The centuries-old practice of drying cut forage crops in the field prior to storage usually results in the production of very low quality hay. Such a procedure subjects the crops to uncontrolled natural elements, such as sun, rain and variable temperatures, which attack and decompose the crop. As a result, many of the nutrients in the crop, such as the xantophylls, carotene, chlorophyll and the very important proteins, are lost in the drying process.
And, yet, these crops cannot be stored in the wet condition they are in immediately following cutting. Such storage prompts rotting and molding of the hay and can even result in spontaneous combustion. So numerous proposals have been made for artificially drying the hay either prior to or during storage. One hay drying device, which exemplifies prior efforts to improve the quality of hay, is disclosed in U.S. Pat. No. 2,602,728, granted July 1, 1952, to Herman C. Erfurth for "Hay Drying Device". The Erfurth apparatus is adapted to be installed in a barn loft, hay mow or hay stack to direct heated streams of drying air into hay stacked over and around the apparatus. A plurality of cylindrical flue formers are disposed at spaced intervals in a layer of hay and receive air under pressure through flue feeder channels in the layer of hay. Drying air exiting the flue formers and the feeder channels is allowed to percolate upwardly through the layers of hay, gathering moisture which is then carried to the atmosphere. As additional layers of hay are stacked above the dried layer or layers the flue formers are raised to form air flow flues in the new layers.
One of the problems with the Erfurth hay drying apparatus and others like it is that it provides no means for controlling the flow of drying air through the layer of hay. The natural upward percolation of drying air exiting the flues and the flue feeder channels results in very little lateral dispersion of the drying air. Consequently, regions of the hay layer remote from a flue of a feeder channel may receive little or no air flow. In addition, regions of the hay layer which happen to be more tightly packed than other regions similarly are deprived of any flow of drying air. The result is a layer of hay with very uneven drying throughout. Those undried regions of hay are subject to deterioration through molding or combustion.
Furthermore, the Erfurth apparatus is designed to rest on and project above the surface on which the hay to be dried is placed. Thus, the apparatus is in the way of and interferes with removal of the dried hay.
There continues to be a need, therefore, for a hay drying facility capable of uniformly and controllably drying the hay in such manner that there is maximum retention of the nutrients in the hay.